ORIGINAL ARTICLE

Development and Validation of the GI-Cognitions Questionnaire

Melissa G. Hunt • Elisabeth Ertel • Jordan A. Coello •

Lauren Rodriguez

� Springer Science+Business Media New York 2014

Abstract Patients with irritable bowel syndrome (IBS)

have been shown to have catastrophic cognitions regarding

the social and occupational consequences of GI symptoms.

Moreover, the efficacy of cognitive–behavioral therapy for

IBS may be partially mediated by reductions in such cog-

nitions. We aimed to develop and validate a short self-

report measure of GI specific catastrophic cognitions. The

GI-Cognitions Questionnaire (GI-Cog) was administered to

a total of 291 participants, including 65 IBS patients, 114

Crohn’s disease patients, 22 patients with co-morbid Cro-

hn’s and IBS and 90 healthy controls. The GI-Cog showed

high internal consistency (a = .92) and good test re-test

reliability (r = .87) as well as good factor structure. It

discriminated between IBS patients, Crohn’s disease

patients and normal controls, and explained unique vari-

ance in GI symptom severity. The GI-Cog is a short, easy-

to-administer self-report measure of GI specific cata-

strophic cognitions that appears to be both reliable and

valid and can be used in future research on vulnerability,

treatment outcome and mediators of treatment efficacy.

Keywords Catastrophizing � Cognitive–behavioral �Crohn’s disease � IBS � Irritable bowel syndrome

Introduction

Irritable bowel syndrome (IBS) is a functional gastroin-

testinal disorder characterized by recurrent abdominal

pain or discomfort associated with improvement with

defecation; a change in the frequency of stool; and/or a

change in the form or appearance of stool (Longstreth

et al. 2006). In addition to these formal diagnostic criteria

issued by the Rome III workgroup (the arm of the non-

profit Rome Foundation tasked with developing diagnostic

criteria for all functional gastrointestinal disorders)

(Drossman 2006), other symptoms associated with IBS

include bloating, urgency and straining during defecation.

These diagnostic criteria, however, do not fully capture

the burden of illness experienced by many IBS patients

(Lembo et al. 2005). IBS diarrhea is often associated with

burning, cramping abdominal pain and feelings of

urgency, which can significantly disrupt social, occupa-

tional and recreational activities. IBS patients experience

significant reductions in quality of life in a range of areas

including health, vitality, social and occupational func-

tioning, pain, diet, sexual function, and sleep (Luscombe

2000; Cho et al. 2011).

The level of disability, distress and dysfunction experi-

enced by IBS patients does not seem to be explained,

however, by the relatively benign physical symptoms and

is not correlated with actual intestinal motility disturbances

(Lackner and Quigley 2005). Moreover, numerous studies

have shown high levels of co-morbidity between IBS and

psychiatric disorders (Lydiard et al. 1993; Sykes et al.

2003; Gros et al. 2009), particularly Panic Disorder (e.g.

Maunder 1998; Kaplan et al. 1996). Indeed, several studies

have demonstrated that successful treatment of Panic Dis-

order often results in significant reductions in IBS symp-

toms (e.g. Noyes et al. 1990).

The development and validation of the GI-COG was presented in

poster format at the 2009 annual meeting of the Association of

Behavioral and Cognitive Therapies as the IBS Cognitions

Questionnaire.

M. G. Hunt (&) � E. Ertel � J. A. Coello � L. Rodriguez

Department of Psychology, University of Pennsylvania, 3720

Walnut Street, Philadelphia, PA 19104-6241, USA

e-mail: mhunt@psych.upenn.edu

123

Cogn Ther Res

DOI 10.1007/s10608-014-9607-y

Cognitive models of Panic Disorder suggest that panic is

often precipitated by catastrophic misinterpretations of

bodily sensations (Clark 1986; Casey et al. 2004) along

with high levels of anxiety sensitivity and somatic hyper-

vigilance (Perez et al. 2009; Schmidt et al. 2003). There is

evidence that IBS patients are prone to similar cognitive

processes. IBS patients have been shown to be hypervigi-

lant to GI sensations (Posserud et al. 2009) and are high in

anxiety about visceral sensations (Hazlett-Stevens et al.

2003; Labus et al. 2004; Labus et al. 2007). Recent work

has suggested that IBS patients also show illness specific

catastrophic cognitions such as pain-catastrophizing (Gros

et al. 2009; Lackner et al. 2004b). IBS patients also hold a

number of catastrophic and dysfunctional beliefs about IBS

symptoms and about the social and occupational implica-

tions of those symptoms (Hunt et al. 2009a). Moreover,

reductions in IBS specific catastrophic thinking were

shown to partially mediate the efficacy of cognitive–

behavioral treatment for IBS in one recent clinical trial

(Hunt et al. 2009b).

Indeed, the beliefs of IBS patients look more like the

catastrophic beliefs of Panic patients, than they look like the

beliefs of most patients with Crohn’s Disease, an inflam-

matory bowel disease (Hunt et al. 2009a). Crohn’s patients

are a particularly relevant comparison group, as Crohn’s

shares many symptoms with IBS (especially abdominal

pain and diarrhea) and has many serious, potentially life

threatening complications. Nevertheless, Crohn’s patients

typically exhibit lower rates of psychiatric co-morbidity

than do IBS patients (Walker et al. 1990, North and Alpers

1994) and also show less propensity towards catastrophic,

distorted beliefs about their symptoms (Hunt et al. 2009a).

In a comprehensive review of cognitive and behavioral

therapies for IBS, Blanchard (2005) noted that the efficacy

of CBT for IBS seems due, at least in part, to changes in

the maladaptive cognitive processes that underlie IBS. He

notes that almost all CBT treatment protocols involve

psychoeducation about the GI system and the link between

IBS and stress, and that this undoubtedly marks the

beginning of cognitive change for patients. He also pointed

out that while most interventions include a relaxation

training component, relaxation-only conditions typically do

not do well. Two prior RCTs of CBT for IBS (Greene and

Blanchard 1994 and Payne and Blanchard 1995) attempted

to measure cognitive change with two standard (not IBS

specific) measures of maladaptive cognitions. These

included the Dysfunctional Attitude Scale (Weissman and

Beck 1978) and the Automatic Thoughts Questionnaire

(Hollon and Kendall 1980). Both studies found that mal-

adaptive cognitions declined significantly in the cognitive

therapy groups, but not in the symptom monitoring groups,

and that cognitive change was correlated with change in GI

symptoms.

Toner et al. (1998) developed a measure that is more

specific to the cognitions associated with IBS. The Cog-

nitive Scale for Functional Bowel Disorders (CS-FBD) was

designed to reflect a number of a priori themes, some of

which are directly related to GI symptoms like pain ca-

tastrophizing (e.g. ‘‘Bowel symptoms are agony’’), some of

which are related to social and occupational implications of

having IBS (e.g. ‘‘With frequent bathroom visits, others

think something is wrong’’) and a number of which are

related to more general themes of perfectionism and poor

self-care, but are not specific to GI symptoms (e.g. ‘‘Being

late upsets me’’ ‘‘Hate making a fool of myself’’ and

‘‘Feeling guilt if I nurture myself’’).

Toner’s scale, like the DAS and the ATQ, has proved

somewhat sensitive to treatment related changes during

CBT for IBS. Tkachuk et al. (2003) found that while the

CS-FBD changed significantly over the course of CBT, it

did not correlate well with IBS symptom change, which

was minimal in in their trial. Drossman et al. (2003) also

found that patients in the CBT condition changed signifi-

cantly on the CS-FBD. They also obtained significant

reductions in IBS symptoms, but changes on the CS-FBD

were related to some indices of change (like patient global

ratings of satisfaction) but not to others (like pain). Blan-

chard (2005, page 118) concluded that change on the CS-

FBD ‘‘does not seem related to symptomatic change.’’ This

is disappointing, but could be due to the inclusion of items

reflecting many maladaptive cognitions that might be

expected to change with good CBT, but are not actually

specific to GI symptoms.

There are good measures of IBS symptom severity

(Svedlund et al. 1988; Wiklund et al. 2003), quality of life

(Drossman et al. 2000) and visceral sensitivity (VSI, Labus

et al. 2007). The VSI captures an individual’s anxiety about

GI sensations (e.g. ‘‘When I feel discomfort in my belly, it

frightens me’’), hypervigilance and awareness of GI sen-

sations (e.g. ‘‘I am constantly aware of the feelings I have

in my belly’’), and fear and avoidance of food related sit-

uations (e.g. ‘‘I get anxious when I go to a new restau-

rant’’). It does not address why people are hypervigilant,

frightened and avoidant (i.e. because they have cata-

strophic beliefs about what might happen when they go to a

new restaurant). In some other studies of IBS specific

beliefs (Hunt et al. 2009a, b) catastrophic cognitions were

elicited as free responses to hypothetical scenarios, which

then needed to be coded by blind raters. Such methodology

is cumbersome and time consuming, and cannot be easily

disseminated for use in clinical trials. Thus, the goal of the

current study was to develop and provide initial validation

of a brief, easy-to-score, self-report measure of GI-specific

catastrophic cognitions. We hypothesize that this new

measure that captures GI-specific catastrophic cognitions

will discriminate between IBS, Crohn’s, and healthy

Cogn Ther Res

123

controls and will predict GI-symptom severity and quality

of life over and above existing measures of gastrointestinal

symptom-specific anxiety.

Method

Subjects

A total of 291 participants (213 female, 78 male) com-

pleted the study, including 65 IBS patients, 114 Crohn’s

patients, 22 patients with self-reported co-morbid Crohn’s

and IBS and 90 healthy controls with no reported GI dis-

orders. Ages ranged from 18 to 69 years (mean = 33.5

median = 29.5). Summary demographic data are presented

in Table 1.

Inclusion criteria for the IBS only group consisted of

participant self-report that they had been diagnosed with

IBS by a medical professional, but denied being diagnosed

with an inflammatory bowel disease. IBS patients also

completed a self-report checklist of the Rome Diagnostic

Criteria for IBS. They were excluded if they did not meet

criteria for IBS based on this structured questionnaire. That

is, subjects had to endorse abdominal pain or discomfort

occurring at least 2–3 days a month (for women, not

exclusively during menstruation) for at least 6 months. The

pain had to remit with defecation at least some of the time,

and the onset of the pain had to be associated with a change

in the form of the stool at least some of the time. We did

not evaluate the presence of other functional gastrointes-

tinal disorders (FGIDs) such as functional dyspepsia.

Inclusion criteria for the Crohn’s group consisted of

participant self-report that they had been diagnosed with

Crohn’s Disease by a medical professional. A subset of the

Crohn’s patients also reported that they had been diagnosed

with co-morbid IBS, but those individuals did not confirm

the diagnosis with the Rome questionnaire. Healthy con-

trols were included if they denied a diagnosis of any gas-

trointestinal disorder including IBS, Crohn’s,

Gastroesophageal Reflux Disease (GERD) and Ulcerative

Colitis (UC). Healthy controls were not screened for any

other conditions.

IBS patients, Crohn’s patients, and healthy controls

were all recruited via the Internet. Invitational messages for

individuals diagnosed with IBS were posted on IBS spe-

cific websites that offered a support group or forum, while

invitational messages for individuals diagnosed with Cro-

hn’s were posted on Crohn’s specific websites. Some

example websites we posted on include: Facebook, ibs-

group.org, HealingWell.com, MDjunction, Crohn’s Forum,

and Crohn’s Zone. Healthy controls were recruited via the

websites Craigslist and Mechanical Turk (MTurk) via

Amazon with messages requesting the participation of

individuals with no diagnosis of IBS, gastro-esophageal

reflux disease, ulcerative colitis or Crohn’s disease. Addi-

tional healthy control subjects were recruited from the

undergraduate population at the University of

Pennsylvania.

Table 1 Demographic information

Diagnosis Statistical test

Controls Crohn’s IBS IBS/Crohn’s

n 90 114 65 22

Mean age 28.65 (n = 85) 37.47 (n = 73) 36.20 (n = 44) 33.09 (n = 22) F(3, 220) = 8.06, p \ .001

Gender v2(3, 291) = 20.90, p \ .001

Female 50 91 54 18

Male 40 23 11 4

Marital status v2(12, 291) = 32.13, p = .001

Divorced 3 7 4 0

Married 27 63 29 16

Single 59 39 30 5

Separated 0 2 2 0

Widowed 1 3 0 1

Ethnicity v2(18, 291) = 63.39, p \ .001

Asian 32 2 7 2

Black 0 2 2 0

Hispanic 4 0 1 0

Caucasian 52 106 52 19

Other 2 4 2 1

Cogn Ther Res

123

The study was approved by the University of Pennsyl-

vania’s Internal Review Board.

Measures

Rome III Questionnaire

The Rome III IBS-specific Questionnaire is a widely used

10-item self-report scale that covers the diagnostic criteria

for IBS. It has been found to have acceptable sensitivity

and high specificity as well as good test–retest reliability

(Whitehead et al. 2006).

Visceral Sensitivity Index (VSI)

The VSI (Labus et al. 2004, 2007) is a unidimensional,

15-item scale that measures gastrointestinal symptom-

specific anxiety. It has high internal consistency, (a = .93)

and a mean inter-item correlation of .47 (Hazlett-Stevens

et al. 2003; Labus et al. 2004). It has good criterion, con-

struct and predictive validity (Labus et al. 2007).

Gastrointestinal Symptom Rating Scale-IBS (GSRS-IBS)

The GSRS (Wiklund et al. 2003) is a 13 item self-report

scale that measures GI symptom severity across five

domains (bloating, diarrhea, constipation, pain, and sati-

ety). Each domain has demonstrated high internal consis-

tency, with Cronbach’s alpha ranging from .74 (pain) to .85

(satiety). The scale also demonstrates high test–retest

reliability between the five factors (all r = .55–.70), and

good convergent validity (Wiklund et al. 2003).

Gastrointestinal Cognitions Questionnaire (GI-Cog)

The authors reviewed online IBS discussion forums to

determine common catastrophic thoughts and themes about

the implications of GI symptoms. Patient records from a

past cognitive–behavioral treatment study of IBS (Hunt

et al. 2009b) were also available for review. The initial

item pool for the GI-Cog was developed to reflect the types

of catastrophic fears that are often described clinically by

IBS patients undergoing cognitive–behavioral therapy. In

addition, items were developed to reflect the experiences

and fears IBS patients shared on a number of on-line for-

ums. The item pool was also chosen to reflect the areas that

prior cognitive theories of IBS have explored (Hunt et al.

2009a).

Items included thoughts about Social Embarrassment

(‘‘Having to deal with IBS is incredibly embarrassing’’),

Perceived Incompetence (‘‘If I have to interrupt a meeting

to go to the bathroom it will be awful and people will think

I’m incompetent or unreliable’’), Avoidance/Life

Interference (‘‘When my IBS acts up I have to cancel my

plans and miss out on important parts of my life’’), and

Urgency/Incontinence (‘‘If I feel the urge to defecate and

cannot find a bathroom right away I won’t be able to hold it

and I’ll be incontinent’’). A total of 18 items were included.

Subjects are asked to rate the degree to which they believe

the statements on a 5 point scale ranging from 0 (hardly at

all) to 4 (very much).

Although similar to the VSI in that it aims to identify

gastrointestinal related anxiety in sufferers of IBS, the GI-

Cog focuses more directly on the catastrophic cognitions

IBS sufferers experience that give rise to anxiety and

avoidance. That is, the cognitive–behavioral model of

psychopathology requires not only that we measure mal-

adaptive fear and avoidance, but that we elucidate the

underlying cognitions that presumably cause the anxiety to

occur.

Consistent with FDA guidelines on the development of a

patient-reported outcome measure (FDA PRO guidelines),

initial pilot testing of the draft instrument led to changes in

wording to ensure that we were targeting the intended

population. Because we wanted the questionnaire to be

equally appropriate for all individuals (not just those with

IBS) the term ‘‘IBS’’ was replaced with the term ‘‘gut’’ or

‘‘gut problems.’’ For example, the item ‘‘Having to deal

with IBS is incredibly embarrassing’’ became ‘‘Having to

deal with gut problems is incredibly embarrassing.’’

Irritable Bowel Syndrome Quality of Life (IBS-QoL)

The IBS-QoL is a 34 item self-report scale that measures

impairment in quality of life secondary to bowel problems

(Patrick et al. 1998). Items are rated on a Likert scale

ranging from 1 (not at all) to 5 (a great deal/extremely).

Summed, standardized scores range from 0 (not at all

impaired) to 100 (extremely impaired). The IBS-QoL has 8

subscales, including dysphoria, interference with activity,

body image, health worry, food avoidance, social reaction,

sexual, and relationship. The IBS-QoL has high internal

consistency (Cronbach’s a = .95), as well as high test–

retest reliability and good construct validity (Patrick et al.

1998). Items on the IBS-QoL refer to ‘‘bowel problems’’

and so are equally applicable to individuals with Crohn’s

and healthy controls. To avoid confusion among our sub-

jects, we referred to the measure as the ‘‘GI-QoL’’ but did

not change any item content or wording.

Procedure

Subjects viewed an invitational message on-line and fol-

lowed a link to the study’s home page where they read

about the study and provided consent. Individuals who

entered via an IBS support group forum completed a Rome

Cogn Ther Res

123

Criteria Questionnaire, while those that entered through a

Crohn’s Disease or normal control website did not. All

subjects completed a demographics questionnaire, the GI-

Cog, the VSI, the GSRS, and the IBS-QoL. Participants

were given the option of providing an email address in

order to be contacted for a follow up survey. Those par-

ticipants who provided their e-mail were asked to complete

the GI-Cog again approximately 1 week later, which pro-

vided us with test–retest data for the questionnaire from a

portion of the sample.

Statistical Analyses

To determine the comparability of our samples, we used Chi

square tests to examine diagnostic group differences on

demographic variables excluding age. Age differences

between groups were evaluated using a one-way analysis of

variance (ANOVA) and Tukey’s honestly significant dif-

ference (Tukey’s HSD) tests to correct for multiple com-

parisons. We then explored diagnostic group differences in

symptom severity, visceral sensitivity, and quality of life

separately using ANOVA and Tukey’s HSD tests. The pain,

diarrhea, and constipation symptom severity of our sample

was assessed using Wiklund et al. (2003) GSRS norms for

moderate and severe Rome-diagnosed IBS.

Each of the 18 items on the GI-Cog was tested individ-

ually for discriminative validity using independent t tests

comparing the IBS patients to the normal controls. Items

that did not discriminate were dropped. Dropped items were

then each analyzed using a one-way ANOVA to determine

if the item was able to discriminate between the diagnostic

groups to evaluate for possible re-inclusion in the GI-Cog.

Internal consistency and test–retest reliability were assessed

using Cronbach’s a and Pearson correlations.

Once the non-discriminating items were removed, we

examined the factorability of the remaining items. One

useful test of factorability is the Kaiser–Meyer–Olkin

(KMO) measure of sampling adequacy (Dziuban and

Shirkey 1974). The critical value for this test is .50, with

values above .7 being considered ‘‘middling’’, values above

.8 being considered ‘‘meritorious’’ and values above .9

being considered ‘‘marvelous.’’ After confirming that the

GI-Cog was appropriate for factor analysis, meeting the

assumptions of sampling adequacy and sphericity using the

KMO and Bartlett’s test of sphericity and verifying that the

selected items should be included in the factor analysis by

examining the anti-image matrix and communalities, we

analyzed the remaining items using principal component

analysis with Varimax (orthogonal) rotation and Kaiser

Normalization. Principal component analysis was used to

identify underlying constructs and compute composite

scores for factors. Items with Eigenvalues greater than 1

were extracted.

To assess the discriminative and predictive validity of

our measure, we tested whether the GI-Cog discriminated

by diagnosis and predicted GI symptom severity and

quality of life using a univariate general linear model with

diagnosis as a fixed factor and Tukey’s HSD. Pearson

correlations were used to examine if the GI-Cog converged

with the VSI. Finally, to determine whether the GI-Cog

explains unique variance in symptom severity above and

beyond visceral sensitivity, we conducted an ANCOVA

predicting symptom severity by diagnosis, with the VSI

and the GI-Cog entered as covariates. All analyses were

completed using SPSS for Windows, Version 20.0.

Results

Comparability of Samples

There were significant between group differences on sev-

eral demographic variables. The diagnostic groups differed

on gender, v2(3, 291) = 20.90, p \ .001, marital status,

v2(12, 291) = 32.13, p = .001, and race, v2(18,

291) = 63.39, p \ .001, but not education, v2(24,

291) = 28.08, p = .26. A one-way ANOVA was con-

ducted to determine group differences in age, F(3,

220) = 8.06, p \ .001. Tukey’s HSD revealed that the

control group (M = 28.65, SD = 12.38) was significantly

younger than the Crohn’s disease group (M = 37.47,

SD = 12.04) and the IBS group (M = 36.20,

SD = 12.12). Individuals in the control group were also

more likely to be single, male and/or Asian, reflecting the

age and race demographics of the University of Pennsyl-

vania. However, the Crohn’s and IBS groups did not differ

significantly on any of the demographic variables. To

correct for possible bias, all analyses were also re-run with

a restricted sample of white women only. See Table 1 for

summary demographic data.

Symptom Severity, Visceral Sensitivity and Quality

of Life

There were significant group differences in GI symptom

severity, visceral sensitivity, and quality of life. We con-

ducted separate ANOVAs predicting scores on the GSRS,

VSI, and IBS-QoL by diagnosis and all ANOVAs were

highly significant (all F [ 49.0, all p \ .001). For symp-

tom severity as measured by GSRS, Tukey’s HSD revealed

that all diagnostic groups were significantly different from

each other (p \ .01), except for IBS and IBS/Crohn’s

groups, which did not differ significantly (p = .42). Con-

trols had the lowest symptom severity, followed by Cro-

hn’s patients, with IBS and IBS/Crohn’s patients notably

having the highest severity scores. These results were the

Cogn Ther Res

123

same when the sample was restricted to white women only.

For both visceral sensitivity and quality of life, Tukey’s

HSD revealed that only controls were significantly differ-

ent from Crohn’s, IBS, and IBS/Crohn’s patients

(p \ .001), while there were no significant differences

among the remaining groups. The same was the case for

the restricted sample for quality of life. For the VSI, in the

restricted sample, controls scored significantly lower than

all patient groups on the VSI, followed by individuals with

Crohns, who scored lower than individuals with IBS and

comorbid IBS and Crohn’s. See Table 2 for means and SDs

on all measures by diagnosis.

Our IBS sample’s GSRS scores on the Rome III relevant

criteria of pain and altered bowel habits (diarrhea and

constipation) were directly comparable to the norms for

patients with moderate, Rome diagnosed IBS reported by

Wiklund et al. (2003). For diarrhea, the moderate sample’s

mean score was 3.6 (SD 1.5), while our sample had a mean

score of 3.89 (SD 1.83). For constipation, the moderate

sample’s mean score was 2.9 (SD 1.8) while our sample

had a mean score of 2.59 (SD 2.32). Finally, for the pain

dimension our sample was comparable to patients with a

moderate to bordering on severe Rome diagnosis. For the

pain dimension, Wiklund and colleagues reported a mean

score of 3.9 (SD 1.1) for the moderate sample and a mean

score of 5.0 (SD 1.1) for the severe sample, while our

sample had a mean score of 4.44 (SD 1.62).

Item Reduction

Each of the 18 items on the GI-Cog was tested individually for

discriminative validity by conducting independent t tests

comparing the IBS patients to the normal controls. Two

questions were dropped because of their failure to discriminate

between these groups. In the terminology of item response

theory these items were ‘‘too easy’’ and were endorsed equally

by everyone in the sample. A one-way ANOVA was con-

ducted for each of the dropped items to determine if the item

was able to discriminate between the diagnostic groups, but

there were no significant group differences in either analysis.

[‘‘If I fart, people around me will think I’m crude,’’ F(3,

284) = .69, p = .56, and ‘‘If I bring my own food to a social

gathering, people will think I’m weird,’’ F(3, 287) = .65,

p = .58]. This left a total of 16 items. See Appendix for final

GI-Cog item content and scoring.

Reliability

The remaining 16 items showed excellent internal consis-

tency reliability (a = .92). In addition, the questionnaire

showed strong 1 week test–retest reliability in the sub-

sample of subjects who agreed to be contacted for follow-

up data collection (n = 87, r = .87, p \ .001, n = 87).

The follow-up sample included 45 controls, 26 individuals

with Crohn’s disease and 16 individuals with IBS.

Factor Structure

The factorability of the remaining 16 GI-Cog items was

examined. All 16 items were correlated at least .40 with at

least one other item, which suggested reasonable factor-

ability. Additionally, an examination of the Kaiser–Meyer–

Olkin measure of sampling adequacy was .92, well above

the recommended value of .6 and the critical value of .5,

and Bartlett’s test of sphericity was significant (v2

(120) = 2,815.57, p \ .001). The diagonals of the anti-

image matrix were all over .5, which supported the inclu-

sion of each item in the factor analysis, and all initial

communalities were 1.0. All of these indicators confirmed

that the items shared common variance with other items,

and thus factor analysis was conducted.

We then analyzed the remaining 16 items using principal

component analysis with Varimax (orthogonal) rotation and

Kaiser Normalization. Principal components analysis was

used because the purpose was to identify underlying con-

structs and compute composite scores for factors. We used

the extraction rule of Eigenvalues greater than 1. A three-

factor solution emerged that explained 65 % of the total

variance. Table 3 shows the factor loadings after rotation.

The solution yielded interpretable dimensions reflecting

pain/life interference (items 1, 9, 10, 11, 12, 14, 15, and 16),

social anxiety (items 4, 5, 6, 7, 8, 13, 15 and 16), and disgust

sensitivity (items 2, 3, and 15). The first factor accounted

for 28 % of the variance. The second factor accounted for

an additional 25 % of the variance and the third factor

explained an additional 11 % of the variance.

Table 2 Measures of symptom severity, visceral sensitivity and

quality of life scores for diagnostic groups

Measure Diagnosis F g2

Control Crohn’s IBS IBS/

Crohn’s

GSRS 14.19a

(14.89)

39.94b

(18.62)

48.73

(18.46)

52.23

(18.29)

64.38*** .42

VSI 15.39a

(13.57)

48.91

(15.49)

52.63

(15.11)

53.68

(11.88)

118.21*** .56

IBS-Qol 11.20a

(17.20)

54.86

(23.22)

52.99

(21.96)

62.37

(18.82)

49.82*** .47

Standard deviations appear in parentheses below means

GSRS Gastrointestinal Symptom Rating Scale, VSI Visceral Sensi-

tivity Index, IBS-QoL Irritable Bowel Syndrome Quality of Lifea Significantly different from all other groupsb Significantly different from IBS and IBS/Crohn’s

*** p \ .001

Cogn Ther Res

123

Mean composite scores for each of the factors were

computed for each diagnosis. Higher scores on these fac-

tors indicate greater catastrophizing. See Table 4 for

descriptive statistics on all factors based on diagnosis. We

examined the internal consistency of each of the scales

using Cronbach’s alpha, which reflected low (disgust sen-

sitivity a = .67) to high (pain/life interference a = .91,

social anxiety a = .89) internal consistency. In all three

subscales, eliminating additional items resulted in no sub-

stantial increases in Cronbach’s alpha.

Discriminative Validity

A one-way ANOVA was conducted to determine the

relationship between the GI-Cog scores and diagnosis and

was found to be significant [F(3, 287) = 43.92, p \ .001].

These results were unchanged when we included age and

sex as a covariates and neither age nor sex was a significant

predictor of GI-Cog scores above and beyond diagnosis

[F(1,223) = .56, ns and F(1,223) = .001, ns respectively].

The results also remained unchanged when we restricted

the sample to white women only across all groups. A Tu-

key’s HSD revealed that the control group (M = 16.30,

SD = 10.68) was significantly different from the Crohn’s

disease group (M = 30.39, SD = 12.12), the IBS group

(M = 37.66, SD = 15.34), and the IBS/Crohn’s group

(M = 35.32, SD = 10.27). IBS patients scored signifi-

cantly higher than both Crohn’s patients (p = .001) and

controls (p \ .001). Crohn’s patients in turn scored

significantly higher than normal controls (p \ .001). There

was a moderate effect in the crucial comparison between

IBS and Crohn’s patients, t (110) = 3.28, p = .001,

d = .53.

Convergent Validity

As expected, the GI-Cog was significantly correlated with

the VSI in the entire sample (r = .76, p \ .001) and for

both women and men separately (r = .76, and r = .75,

both p \ .001).

Predictive Validity

The GI-Cog was also significantly correlated with GI

symptom severity as measured by the GSRS (r = .66,

p \ .001) and with impairments in quality of life as mea-

sured by the IBS-QoL (r = .70, p \ .001). Again correla-

tions for women and men were no different. (For the

GSRS, r = .67 and r = .65, both p \ .001; for the IBS-

QoL, r = .70 and r = .72, both p \ .001.) See Table 5 for

all between measure correlations.

Discriminant Validity

To determine whether the GI-Cog explains unique variance

in symptom severity above and beyond visceral sensitivity,

we conducted an ANCOVA predicting symptom severity

scores (GSRS) by diagnosis, with the VSI and the GI-Cog

as covariates. The VSI [F(1, 274) = 39.88, p \ .001] and

the GI-Cog [F(1, 274) = 10.13, p \ .01] both remained

significant predictors of symptom severity above and

beyond diagnosis, suggesting that they each contribute

unique variance and are not simply measuring the same

underlying construct. We also ran these analyses excluding

the control subjects. Results were essentially identical with

both the VSI and the GI-Cog continuing to predict unique

variance in symptom severity and quality of life above and

beyond diagnosis. In addition, we tested the interaction

effects between diagnosis and the GI-Cog and the VSI.

Table 3 Gastrointestinal Cognitions Questionnaire factor loadings

Pain/life

interference

Social

anxiety

Disgust

sensitivity

Communalities

GI-Cog Q1 .57a .15 .32 .45

GI-Cog Q2 .24 .09 .74a .62

GI-Cog Q3 .15 .18 .77a .65

GI-Cog Q4 .10 .71a .10 .52

GI-Cog Q5 .38 .67a .31 .69

GI-Cog Q6 .27 .70a .33 .67

GI-Cog Q7 .31 .72a .02 .62

GI-Cog Q8 .12 .77a .15 .63

GI-Cog Q9 .80a .18 .17 .71

GI-Cog Q10 .88a .20 .09 .82

GI-Cog Q11 .86a .21 .13 .80

GI-Cog Q12 .82a .22 .17 .75

GI-Cog Q13 .19 .77a .00 .64

GI-Cog Q14 .63a .37 .18 .56

GI-Cog Q15 .48 .49 .43 .66

GI-Cog Q16 .56a .51a .15 .58

a Correlations in the range .50–.90

Table 4 Descriptive statistics for the Gastrointestinal Cognitions

Questionnaire dimensions

Pain/life

interference

factor

Social

anxiety

factor

Disgust

sensitivity

factor

Control .77 (.74) .92 (.74) 1.90 (.96)

Crohn’s 2.15 (.89) 1.41 (.93) 2.60 (.93)

IBS 2.58 (1.05) 2.01 (1.13) 2.85 (1.12)

IBS/Crohn’s 2.42 (.65) 1.79 (.87) 2.59 (.91)

Means are listed first followed by SD in parentheses

Cogn Ther Res

123

None of the interaction terms even approached signifi-

cance, and thus were dropped.

Discussion

The results of this study suggest that the GI-Cog is a

reliable and valid measure for assessing catastrophic cog-

nitions in patients with GI disorders. The measure has

excellent internal consistency and 1 week test–retest reli-

ability. It had good discriminative validity and was able to

differentiate between patients with IBS and normal con-

trols with no gastrointestinal disorder. It also was able to

discriminate between patients with IBS and Crohn’s Dis-

ease, with IBS patients scoring significantly higher even

though their symptom severity and visceral sensitivity were

comparable to the Crohn’s group. Perhaps even more

importantly, the GI-Cog was somewhat useful in identify-

ing a group of patients with co-morbid Crohn’s and IBS,

suggesting that catastrophic thinking may be a risk factor

for the development of secondary or co-morbid IBS in IBD

patients. The GI-Cog also showed good convergent valid-

ity, as it was strongly correlated with the VSI, as well as

predictive validity in that it correlated well with symptom

severity and quality of life.

The strength of the correlation between the VSI and the

GI-Cog raises the question of whether the GI-Cog has

sufficient discriminant validity. Indeed, visceral anxiety is

probably closely related to catastrophic cognitions. Inter-

estingly, however, the VSI did not discriminate between

IBS patients and Crohn’s patients. This is probably because

the content of the VSI covers fear of visceral sensations

and GI processes, some of which could be exaggerated (in

the case of IBS), but some of which could be realistic (in

the case of Crohn’s). For example, the VSI items ‘‘I often

worry about problems in my belly’’ and ‘‘I often feel dis-

comfort in my belly could be a sign of a serious illness’’ are

appropriate and realistic for Crohn’s patients, but not for

IBS patients. The GI-Cog goes beyond anxiety about vis-

ceral sensations per se and begins to delineate the cata-

strophic, distorted cognitions that may underlie that anxiety

in IBS. This may be why the GI-Cog both effectively

discriminates between IBS and Crohn’s patients and

explains unique variance in GI symptom severity above

and beyond both diagnosis and visceral sensitivity.

This is not to say, however, that Crohn’s patients never

catastrophize or develop distorted cognitions surrounding

their symptoms. On the contrary, Crohn’s patients still

worry about the impact of GI symptoms significantly more

than normal controls, indicating that this patient group

might also benefit from cognitive–behavioral interventions.

Furthermore, the subgroup of participants who indicated a

diagnosis of both IBS and Crohn’s suggests that catastro-

phizing may make Crohn’s patients vulnerable to the

development of secondary IBS, even when their Crohn’s

disease is under good control.

This study had a number of limitations, particularly with

respect to the sample. First, we did not require physician

confirmation of diagnosis for either IBS or Crohn’s Dis-

ease, but relied on patient self-report. It is unlikely that an

individual would claim a diagnosis of Crohn’s disease

without having received the diagnosis from a medical

professional after appropriate diagnostic testing. However,

it is possible that there were some patients with functional

GI disorders alone in the putative Crohn’s group. If any-

thing, this should have made it more difficult for us to

demonstrate discriminative validity. A ‘‘cleaner’’ sample

would presumably have reduced overlap between the two

groups and would have yielded lower mean scores on the

GI-Cog for the Crohn’s group. On the other hand, IBS is

relatively easy to ‘‘self-diagnose’’ and it may be that some

of the individuals within the IBS group would not actually

have met Rome criteria for IBS had more stringent diag-

nostic procedures been in place. Thus, some individuals in

our IBS sample may not actually have met severity or

duration criteria for IBS. Similarly, however, including

sub-syndromal individuals in the sample should bias the

results against us, making it more difficult to establish

discriminative validity between the IBS group and the

healthy controls. In addition, when comparing the IBS

samples’ symptom severity to existing norms, on average

our IBS sample was in the moderate range of severity.

Since our IBS group scored significantly higher on the GI-

Cog than both the Crohn’s group and the healthy controls

despite these limitations, we can assume that our findings

might have been stronger had we excluded individuals

based on failing to meet physician confirmed diagnostic

criteria for either IBS or Crohn’s.

With respect to the Crohn’s sample, we do not have

information pertaining to the disease state of individuals.

Some may have been experiencing active symptom flare

ups, while some might have been in remission. This makes

the symptom severity findings a bit hard to interpret. Are

IBS patients reporting greater GI symptom severity than

Table 5 Correlations between measures

GSRS VSI IBSQoL

GI-COG .76* .66* .70*

GSRS .75* .72*

VSI .83*

GI-COG Gastrointestinal Cognitions Questionnaire, GSRS Gastroin-

testinal Symptom Rating Scale, VSI Visceral Sensitivity Index, IBS-

QoL Irritable Bowel Syndrome Quality of Life

* p \ .001

Cogn Ther Res

123

Crohn’s patients who are in remission, or are they reporting

greater severity than Crohn’s patients with active disease?

We cannot be certain about this based on the current data

set. Nevertheless, the GI-Cog refers to stable beliefs about

the impact of GI symptoms when they are happening, and

does not assume that the individual is currently experi-

encing GI symptoms. Indeed, some of the items are

explicitly conditional, such as ‘‘If I’m experiencing a gut

attack and feeling sick, I can’t enjoy or pay attention to

anything else.’’ While it is possible that current disease

state would bias the responses of the Crohn’s patients, it is

also possible that the GI-Cog does indeed capture a stable

vulnerability to catastrophic cognitions that is independent

of current disease status. Future research is needed to

establish how the course of Crohn’s Disease interacts with

catastrophizing and visceral sensitivity.

The second major limitation of our sampling procedure

was that the healthy comparison group was not well mat-

ched demographically to the patient groups in a few

important respects. The control sample was recruited from

college students as well as older adults through online

forums. This sample tended to be single, had higher pro-

portions of Asian participants as well as males, and was

significantly younger on average than both the Crohn’s

disease and IBS patient samples. This limits the general-

izability of the findings with respect to the healthy controls,

and is especially problematic since both males and Asians

tend to have lower prevalence rates of anxiety related

disorders (McLean et al. 2011; Asnaani et al. 2010).

However, we did run several of the analyses controlling for

age and gender, which made no difference at all and we re-

ran a number of the crucial comparisons with a restricted

sample of white women only. Again, the findings were

essentially unchanged. Since the crucial comparisons were

really between the patient groups, which were well-mat-

ched demographically, we believe that this limitation is

less severe than it initially appears.

Another limitation is that other functional disorders

(such as functional dyspepsia) were not ruled out. We

recognize that other functional disorders may be related to

the severity of catastrophic thinking, visceral sensitivity,

symptoms and their impact on quality of life. However, the

GI-Cog focuses specifically on gut distress, not nausea,

heartburn, early satiety or other symptoms of dyspepsia.

Thus, it is unclear how screening such individuals in or out

of the study would have altered the results.

The final limitation of the study is that we were unaware

of the existence of the Cognitive Scale for Functional

Bowel Disorders (CS-FBD) developed by Toner et al.

(1998) which has some conceptual overlap with the GI-

Cog, when we developed our questionnaire. Had we known

about it, we would certainly have included it in the current

study. In one study, the CS-FBD proved to be somewhat

sensitive to therapeutic change during CBT for IBS

(Drossman et al. 2003), but in another study it was unre-

lated to symptom improvement (Tkachuk et al. 2003).

Blanchard (2005) concluded that the CS-FBD did not seem

to be related to symptomatic change, and it has not been

used in any further studies that we are aware of. An

advantage of the GI-COG over the CS-FBD is that the CS-

FBD includes many items that reflect general maladaptive

beliefs that are not GI specific. We hope that the GI-COG

will prove more sensitive to process and outcome changes

in successful CBT for IBS. Nevertheless, an important

future study might directly compare the CS-FBD and the

GI-COG to establish their relative convergent and dis-

criminant validity. We also might have included the Pain

Catastrophizing Scale (Sullivan et al. 1995), which shares

some conceptual overlap with both visceral anxiety and GI

symptom specific catastrophizing.

Despite these limitations, we believe that this study

provides compelling initial validation of a unique measure

of cognitive processes that may be highly relevant to the

development and maintenance of IBS. It has proved to

have good concurrent, predictive and discriminative or

known-groups validity, successfully distinguishing

between IBS patients and Crohn’s patients.

Future research endeavors could benefit from the use of the

GI-Cog not only in understanding IBS, but also in evaluating

the treatment of IBS, and in predicting vulnerability to the

development of secondary IBS in IBD patient populations.

Cognitive–behavioral therapy has been shown to be effective

in the treatment of IBS (e.g., Hunt et al. 2009b; Drossman et al.

2003; Craske et al. 2011; Lackner et al. 2004a; Ljotsson et al.

2011). Good CBT targets both behavioral avoidance and

distorted beliefs about GI symptoms and the implications of

those symptoms for social, occupational and recreational

functioning. The GI-Cog is a short, easy-to-administer self-

report measure that can be used to assess vulnerability, track

changes in catastrophic thinking during treatment and exam-

ine possible process variables underlying successful therapy.

Conflict of Interest Melissa G. Hunt, Elisabeth Ertel, Jordan A.

Coello and Lauren Rodriguez declare that they have no conflict of

interest. This research was unfunded.

Informed Consent All procedures followed were in accordance

with the ethical standards of the responsible committee on human

experimentation (institutional and national) and with the Helsinki

Declaration of 1975, as revised in 2000 (5). Informed consent was

obtained from all patients for being included in the study.

Animal Rights No animal studies were carried out by the authors

for this article.

Cogn Ther Res

123

Appendix

References

Asnaani, A., Richey, J. A., Dimaite, R., Hinton, D. E., & Hofmann, S.

G. (2010). A cross-ethnic comparison of lifetime prevalence

rates of anxiety disorders. Journal of Nervous and Mental

Disease, 198(8), 551–555.

Blanchard, E. B. (2005). A critical review of cognitive, behavioral,

and cognitive–behavioral therapies for irritable bowel syndrome.

Journal of Cognitive Psychotherapy: An International Quarterly,

19(2), 101–123.

Casey, L. M., Oei, T. P., Newcombe, P. A., & Kenardy, J. (2004). The

role of catastrophic misinterpretation of bodily sensations and

panic self-efficacy in predicting panic severity. Journal of

Anxiety Disorders, 18(3), 325–340.

Cho, H. S., Park, J. M., Lim, C. H., Cho, Y. K., Lee, I. S., Kim, S. W.,

et al. (2011). Anxiety, depression and quality of life in patients

with irritable bowel syndrome. Gut and Liver, 5(1), 29–36.

Clark, D. M. (1986). A cognitive approach to panic. Behaviour

Research and Therapy, 24, 461–470.

Craske, M. G., Wolitzky-Taylor, K. B., Labus, J., Wu, S., Frese, M.,

Mayer, E. A., et al. (2011). A cognitive–behavioral treatment for

irritable bowel syndrome using interoceptive exposure to visceral

sensations. Behaviour Research and Therapy, 49, 413–421.

Drossman, D. A. (2006). The functional gastrointestinal disorders and

the Rome III process. Gastroenterology, 130(5), 1377–1390.

Drossman, D. A., Patrick, D. L., Whitehead, W. E., Toner, B. B.,

Diamant, N. E., Hu, Y., et al. (2000). Further validation of the

IBS–QOL: A disease-specific quality-of-life questionnaire.

American Journal of Gastroenterology, 95(4), 999–1007.

Drossman, D. A., Toner, B. B., Whitehead, W. E., Diamant, N. E.,

Dalton, C. B., Duncan, S., et al. (2003). Cognitive–behavioral

therapy versus education and desipramine versus placebo for

moderate to severe functional bowel disorders. Gastroenterol-

ogy, 125, 19–31.

Dziuban, C. D., & Shirkey, E. C. (1974). When is a correlation matrix

appropriate for factor analysis? Some decision rules. Psycho-

logical Bulletin, 81(6), 358–361.

Greene, B., & Blanchard, E. B. (1994). Cognitive therapy for irritable

bowel syndrome. Journal of Consulting and Clinical Psychol-

ogy, 62, 576–582.

Gros, D. F., Antony, M. M., McCabe, R. E., & Swinson, R. P. (2009).

Frequency and severity of the symptoms of irritable bowel

syndrome across the anxiety disorders and depression. Journal of

Anxiety Disorders, 23(2), 290–296.

Hazlett-Stevens, H., Craske, M. G., Mayer, E. A., Chang, L., &

Naliboff, B. D. (2003). Prevalence of irritable bowel syndrome

among university students: The roles of worry, neuroticism,

GI Cognitions Questionnaires (GI-Cog)

Please rate the degree to which you believe each of the following statements Hardly

at all

A little

bit

Moderately A fair

bit

Very

much

1 If I feel the urge to defecate and cannot find a bathroom right away I won’t be able

to hold it and I’ll be incontinent

0 1 2 3 4

2 The thought of fecal incontinence is terrifying. If it happened, it would be awful 0 1 2 3 4

3 If I fart, people around me will be disgusted 0 1 2 3 4

4 If I don’t drink or eat with other people, they will think I’m antisocial and no fun 0 1 2 3 4

5 If I have to get up and leave an event, meeting or social gathering to go to the

bathroom people will think there’s something wrong with me

0 1 2 3 4

6 If I have to interrupt a meeting or presentation at work to go to the bathroom, it will

be awful, and people will think I’m incompetent or unreliable

0 1 2 3 4

7 If I have stop or leave to find a bathroom during an outing or trip my friends and

family will be frustrated and annoyed with me

0 1 2 3 4

8 If I told my coworkers or friends about my gut problems they wouldn’t understand

and would think I was weak or gross

0 1 2 3 4

9 When I feel my GI symptoms acting up, I’m afraid the pain will be excruciating and

intolerable

0 1 2 3 4

10 When my gut acts up, I have to cancel my plans and miss out on important parts of

life

0 1 2 3 4

11 If I’m experiencing a gut attack and feeling sick, I can’t enjoy or pay attention to

anything else

0 1 2 3 4

12 Having a gut attack during an outing or get together ruins the experience 0 1 2 3 4

13 If people knew about my gut problems, they would think about me negatively 0 1 2 3 4

14 If I leave the house without my emergency medicine(s) (e.g. Imodium, Lomotil,

Pepto-Bismol, Gas-Ex, Tums) it could lead to disaster

0 1 2 3 4

15 Having to deal with gut problems is incredibly embarrassing 0 1 2 3 4

16 If people knew what my life was really like they would think I was crazy 0 1 2 3 4

Subscale structure: Pain/life interference: items 1, 9, 10, 11, 12, 14, 15, and 16; Social anxiety: items 4, 5, 6, 7, 8, 13, 15 and 16; Disgust

sensitivity: items 2, 3, and 15

Cogn Ther Res

123

anxiety sensitivity and visceral anxiety. Journal of Psychoso-

matic Research, 55(6), 501–505.

Hollon, S. D., & Kendall, P. E. (1980). Cognitive self-statements in

depression: Development of an Automatic Thoughts Question-

naire. Cognitive Therapy and Research, 4, 383–396.

Hunt, M. G., Milonova, M., & Moshier, S. (2009a). Catastrophizing

the consequences of gastrointestinal symptoms in irritable bowel

syndrome. Journal of Cognitive Psychotherapy: An International

Quarterly, 23(2), 160–173.

Hunt, M. G., Moshier, S., & Milonova, M. (2009b). Brief cognitive–

behavioral internet therapy for irritable bowel syndrome.

Behavior Research and Therapy, 47, 797–802.

Kaplan, D. S., Masand, P. S., & Gupta, S. (1996). The relationship of

irritable bowel syndrome (IBS) and panic disorder. Annals of

Clinical Psychiatry, 8(2), 81–88.

Labus, J. S., Bolus, R., Chang, L., Wiklund, I., Naesdal, J., Mayer, E.

A., et al. (2004). The visceral sensitivity index: Development

and validation of a gastrointestinal symptom-specific anxiety

scale. Alimentary Pharmacology & Therapeutics, 20, 89–97.

Labus, J. S., Mayer, E. A., Chang, L., Bolus, R., & Naliboff, B. D.

(2007). The central role of gastrointestinal-specific anxiety in

irritable bowel syndrome: Further validation of the visceral

sensitivity index. Psychosomatic Medicine, 69, 89–98.

Lackner, J. M., Morley, S., Dowzer, C., Mesmer, C., & Hamilton, S.

(2004a). Psychological treatments for irritable bowel syndrome:

A systematic review and meta-analysis. Journal of Consulting

and Clinical Psychology, 72(6), 1100–1113.

Lackner, J. M., & Quigley, B. M. (2005). Pain catastrophizing

mediates the relationship between worry and pain suffering in

patients with irritable bowel syndrome. Behaviour Research and

Therapy, 43, 943–957.

Lackner, J. M., Quigley, B. M., & Blanchard, E. B. (2004b).

Depression and abdominal pain in IBS patients: The mediating

role of catastrophizing. Psychosomatic Medicine, 66, 435–441.

Lembo, A., Ameen, V. Z., & Drossman, D. A. (2005). Irritable bowel

syndrome: toward an understanding of severity. Clinical Gas-

troenterology & Hepatology, 3(8), 717–725.

Ljotsson, B., Hedman, E., Lindfors, P., Hursti, T., Lindefors, N.,

Andersson, G., et al. (2011). Long-term follow-up of internet-

delivered exposure and mindfulness based treatment for irritable

bowel syndrome. Behaviour Research and Therapy, 49(1), 58–61.

Longstreth, G. F., Thompson, W. G., Chey, W. D., Houghton, L. A.,

Mearin, F., & Spiller, R. C. (2006). Functional Bowel Disorders.

Gastroenterology, 130, 1480–1491.

Luscombe, F. A. (2000). Health-related quality of life and associated

psychosocial factors in irritable bowel syndrome: A review.

Quality of Life Research, 9(2), 161–176.

Lydiard, R. B., Fossey, M. D., Marsh, W., & Ballenger, J. C. (1993).

Prevalence of psychiatric disorder in patients with irritable

bowel syndrome. Psychosomatics, 34(3), 229–234.

Maunder, R. G. (1998). Panic disorder associated with gastrointestinal

disease: Review and hypotheses. Journal of Psychosomatic

Research, 44(1), 91–105.

McLean, C. P., Asnaani, A., Litz, B. T., & Hofmann, S. G. (2011).

Gender differences in anxiety disorders: Prevalence, course of

illness, comorbidity and burden of illness. Journal of Psychiatric

Research, 45(8), 1027–1035.

North, C. S., & Alpers, D. H. (1994). A review of studies of

psychiatric factors in Crohn’s disease: Etiologic implications.

Annals of Clinical Psychiatry, 6(2), 117–124.

Noyes, R., Cook, B., Garvey, M., & Summers, R. (1990). Reduction

of gastrointestinal symptoms following treatment for panic

disorder. Psychosomatics, 31, 75–79.

Patrick, D. L., Drossman, D. A., Frederick, I. O., DiCesare, J., &

Puder, K. L. (1998). Quality of life in persons with irritable

bowel syndrome: Development and validation of a new measure.

Digestive Diseases and Sciences, 43(2), 400–411.

Payne, A., & Blanchard, E. B. (1995). A controlled comparison of

cognitive therapy and self-help support groups in the treatment

of irritable bowel syndrome. Journal of Consulting and Clinical

Psychology, 63, 779–786.

Perez, B., Carlos, I., Shea, M. T., Raffa, S., Rende, R., Dyck, I. R.,et al. (2009). Anxiety sensitivity as a predictor of the clinical

course of panic disorder: A 1-year follow-up study. Depression

and Anxiety, 26(4), 335–342.

Posserud, I., Svedlund, J., Wallin, J., & Simren, M. (2009).

Hypervigilance in irritable bowel syndrome compared with

organic gastrointestinal disease. Journal of Psychosomatic

Research, 66, 399–405.

Schmidt, N. B., Joiner, T. E., Staab, J. P., & Williams, F. M. (2003).

Health perceptions and anxiety sensitivity in patients with panic

disorder. Journal of Psychopathology and Behavioral Assess-

ment, 25(3), 139–145.

Sullivan, M. J. L., Bishop, S., & Pivik, J. (1995). The pain

catastrophizing scale: Development and validation. Psycholog-

ical Assessment, 7, 524–532.

Svedlund, J., Sjodin, I., & Dotevall, G. (1988). GSRS—A clinical

rating scale for gastrointestinal symptoms in patients with

irritable bowel syndrome and peptic ulcer disease. Digestive

Diseases and Sciences, 33(2), 129–134.

Sykes, M. A., Blanchard, E. B., Lackner, J. M., Keefer, L., & Krasner,

S. (2003). Psychopathology in irritable bowel syndrome: Support

for a psychosomatic model. Journal of Behavioral Medicine, 26,

361–372.

Tkachuk, C. A., Graff, L. A., Martin, G. L., & Bernstein, C. N.

(2003). Randomized controlled trial of cognitive–behavioral

group therapy for irritable bowel syndrome in a medical setting.

Journal of Clinical Psychology in Medical Settings, 10, 57–69.

Toner, B. B., Stuckless, N., Ali, A., Downie, F., Emmott, S., & Akman,

D. (1998). The development of a cognitive scale for functional

bowel disorders. Psychosomatic Medicine, 60, 492–497.

Walker, E. A., Roy-Byrne, P. P., Katon, W. J., Li, L., Amos, D., &

Jiranek, G. (1990). Psychiatric illness and irritable bowel

syndrome: A comparison with inflammatory bowel disease.

American Journal of Psychiatry, 147(12), 1656–1661.

Weissman, A., & Beck, A. T. (November, 1978). Development and

validation of the Dysfunctional Attitude Scale: A preliminary

investigation. Presented at the annual meeting of the American

Educational Research Association, Toronto, Ontario, Canada.

Whitehead, W. E., Palsson, O. S., Thiwan, S., Talley, N. J., Chey, W.

D., Irvine, J., et al. (2006). Development and validation of the

Rome III diagnostic questionnaire. In D. A. Drossman, E.

Corazziari, R. C. Spiller, & W. G. Thompson (Eds.), Rome III:

The functional gastrointestinal disorders (3rd ed., pp. 835–853).

McLean, VA: Degnon Associates.

Wiklund, I. K., Fullerton, S., Hawkey, C. J., Jones, R. H., Longstreth,

G. F., Mayer, E. A., et al. (2003). An irritable bowel syndrome-

specific symptom questionnaire: Development and validation.

Scandinavian Journal of Gastroenterology, 38(9), 947–954.

Cogn Ther Res

123